<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <script>
        function Student(age) {
			this.age = age;
		}
		Student.prototype.name = "ss";
		
		var stu1 = new Student(8);
		
		for(var k in stu1) {
			console.log(k);
		}
		
		// age
			// name
			// 为什么age也可以用for in遍历出来
    </script>
</head>
<body>

</body>
</html>